flutter DataTable:列和行属性未定义的问题

import 'package:flutter/material.dart';

DataTable(
  columns: [
    DataColumn(label: Text('列1')),
    DataColumn(label: Text('列2')),
    // 添加更多的列...
  ],
  // 添加行...
)

DataTable(
  columns: [
    DataColumn(label: Text('列1')),
    DataColumn(label: Text('列2')),
  ],
  rows: [
    DataRow(cells: [
      DataCell(Text('行1-列1')),
      DataCell(Text('行1-列2')),
    ]),
    DataRow(cells: [
      DataCell(Text('行2-列1')),
      DataCell(Text('行2-列2')),
    ]),
    // 添加更多的行...
  ],
)

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('DataTable示例')),
        body: Center(
          child: DataTable(
            columns: [
              DataColumn(label: Text('列1')),
              DataColumn(label: Text('列2')),
            ],
            rows: [
              DataRow(cells: [
                DataCell(Text('行1-列1')),
                DataCell(Text('行1-列2')),
              ]),
              DataRow(cells: [
                DataCell(Text('行2-列1')),
                DataCell(Text('行2-列2')),
              ]),
            ],
          ),
        ),
      ),
    );
  }
}